Field of Invention
The present invention relates to packet switch technology. More particularly, the present invention relates to a device and a method for packet switching.
Description of Related Art
With the increasing complexity of network environments, traditional network switches and routers have more and more functions, but lead to low network transmission efficiency. In addition, with the limitations encountered due to the operating system of network hardware equipment, administrators are not allowed to freely manage the transmission paths of the network packets based on requirements. In response, Stanford University of the United States started to promote an experimental technology referred to as “OpenFlow” in 2008 with the expectation that the architecture of open network management would improve network efficiency and satisfy the demand for flexible applications so as to ultimately provide more accurate network management abilities to network service providers.
OpenFlow technology separates the functions of network path control and data packet transmission that are both performed by network switches or routers formerly. The function of network path control is executed by an additional external controller installed with OpenFlow control software. The controller controls the OpenFlow switch by managing a flow table. The flow table includes a group of flow entries, and the flow entries further include match fields, counter and a group of instructions. The OpenFlow switch performs the function of data packet transmission according to a rule in which when a packet matches the match fields of a flow entry, and a specific action of the instructions corresponding to the flow entry is performed.
However, according to the current hardware architecture, a typical OpenFlow switch only supports packet matching of single flow table rather than of multiple flow tables. In other words, each of the packets can only be compared with one flow table. The corresponding instruction or action cannot direct the packet to be compared with other flow tables. Since the conventional hardware architecture does not support the new technology of OpenFlow which supports multiple flow tables, extra costs are required to re-design the architecture so as to conform to the new technology standards.
Therefore, an important area in the field requiring attention is that related designing a new device and method for packet switching that conform to the current standards so as to resolve the above-mentioned problems.